<% if @artwork.categories.length > 0 %>
  <% for category in @artwork.categories %>
    [<%= link_to_remote "x", :update => "categories",
    :url => {:controller => 'admin/artworks', :action => 'remove_category', :id => @artwork.id, :cat => category.id}      
     %>] 
    <%= category.name_with_path %>
    <br/>
  <% end %>
<% else %>
  No categories
<% end %>